Digital television networks generally devote most of their available bandwidth to broadcasting audio and video information. In addition, other information that does not encode video and audio is generally sent in parallel using a small amount of the available bandwidth, typically referred to as an out-of-band network. This other information often includes, but is not limited to, electronic program guide data, conditional access instructions, layout information for a user interface to be displayed, and advertising data. Usually, set-top boxes are designed to gather out-of-band data in parallel with decoding and rendering video and audio data, so that a viewer is free to watch programming while the set-top box accumulates programming data and other information. For example, a cable television broadcast company may broadcast program content over a broadband cable network and broadcast additional related data over a separate smaller band of the same cable network. In this way, a viewer using a client that has at least two tuners can change channels using a first tuner while the client continues receiving the additional data using a second tuner. Alternatively, multiple data streams may be broadcast in parallel over the same channel, allowing a client device with only one tuner to simultaneously receive broadcast program content and broadcast data over the same channel. Because both the quality and number of television channels is a major business point for digital television operators, the amount of bandwidth reserved for the secondary information is usually extremely limited compared to the amount of bandwidth used for broadcasting the video and audio data.
Furthermore, set-top boxes are typically pre-configured to download and display additional data, such as programming data, in a particular language and according to a particular layout. The particular language and layout to be supported is initialized when the set-top box is provisioned, and the user is not given the ability to select another language or layout.